"joebogey" wrote in message
...
Column D has formula =COUNTIF(A1:A15000,A1)

I'm assuming you mean:

=COUNTIF(C$1:C$15000,C1)

Try instead:

=SUM(--(C1=C$1:C$15000))

entered as an array formula with <Ctrl <Shift <Enter.

--

Vasant